Subj : Re: What is the real costs of LOCK on x86 multiprocesor machine?
To   : comp.programming.threads
From : Peter  Dimov
Date : Sun Jul 31 2005 03:43 am

Mirek Fidler wrote:
> > In practice, the actual amortized cost appears to be much lower than
> > 50-100x. I see a 4x difference on shared_ptr_timing_test (which
> > basically tests reference count increments and decrements in a somewhat
> > real-life worst case scenario.)
>
> Have you tested on real MP machine? (4x is close to what I have measured
> on my SP).

No, it was a single P4/2GHz without HT.

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